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In Bangladesh, prawn (Macrobrachium rosenbergii) farming remains dependent on the capture of wild postlarvae as hatchery production is still inadequate. However, prawn postlarvae fishing has been accompanied by concerns over recent climate change. Different climatic variables including cyclone, salinity, sea level rise, water temperature, flood, rainfall, and drought have had adverse effects on coastal ecosystem, thus determining a decline in the availability of prawn postlarvae and thereby catch. The households of postlarvae fishers also face a variety of socioeconomic constraints due to climate change. Considering extreme vulnerability to the effects of climate change, an integrated approach needs to be introduced to cope with the challenges.

AbstractResting egg production is considered the most common form of dormancy in aquatic invertebrates. Given that many taxa at least partially terminate resting egg state using environmental cues, knowledge on environmental drivers of hatching success is important, particularly within the context of climate change and environmental degradation. Fairy shrimp (anostracans) are temporary wetland specialists that are reliant on resting egg production for population persistence. Temporary wetlands are common in many arid regions projected to experience increases in temperature, and in areas often compromised by human‐mediated activities. In this study, we assessed the combined effects of light and temperature on the hatching success of Streptocephalus cafer (Anostraca) dormant eggs from temporary wetlands in an arid environment. Both temperature and light altered hatching success, with emergent effects evident. Light caused a significant threefold increase in hatching success overall, while temperature effects were non‐linear, with hatching optimised at 27°C, and especially under light conditions. These results are discussed within the context of shifting climates and disturbances to temporary wetland ecosystems.

AbstractClimate change will not only shift environmental means but will also increase the intensity of extreme events, exerting additional stress on ecosystems. While field observations on the ecological consequences of heat waves are emerging, experimental evidence is rare, and lacking at the community level. Using a novel “near‐natural” outdoor mesocosms approach, this study tested whether marine summer heat waves have detrimental consequences for macrofauna of a temperate coastal community, and whether sequential heat waves provoke an increase or decrease of sensitivity to thermal stress. Three treatments were applied, defined and characterized through a statistical analysis of 15 years of temperature records from the experimental site: (1) no heat wave, (2) two heat waves in June and July followed by a summer heat wave in August and (3) the summer heat wave only. Overall, 50% of the species showed positive, negative or positive/negative responses in either abundance and/or biomass. We highlight four possible ways in which single species responded to either three subsequent heat waves or one summer heat wave: (1) absence of a response (tolerance, 50% of species), (2) negative accumulative effects by three subsequent heat waves (tellinid bivalve), (3) buffering by proceeding heat waves due to acclimation and/or shifts in phenology (spionid polychaete) and (4) an accumulative positive effect by subsequent heat waves (amphipod). The differential responses to single or sequential heat waves at the species level entailed shifts at the community level. Community‐level differences between single and triple heat waves were more pronounced than those between regimes with vs. without heat waves. Detritivory was reduced by the single heat wave while suspension feeding was less common in the triple heat wave regime. Critical extreme events occur already today and will occur more frequently in a changing climate, thus, leading to detrimental impacts on coastal marine systems.

World fisheries, already vulnerable, are under increasing pressure from the impacts of climate change. Using the Tasmanian rock lobster industry as a case study, we considered the efficacy of risk perception as a tool to inform how to communicate the science of climate change and suggestions for management in relation to development of adaptation strategies for fisheries. Fishers surveyed in this study operate in a fishery that is expected to undergo large changes as a consequence of climate change. Fishers also reported observations of similar large changes in the marine environment and lobster fishery consistent with climate change; yet most fishers surveyed expressed doubts about whether climate change was a real process. The important point for adaption of the industry to climate change is that fisher perceptions of risk tended to create barriers to acceptance of climate change as an issue. This means that there is a barrier to communication and awareness about climate change and thus a barrier to future action on the issue. Improving acceptance of climate change and thus ability to adapt will require the development of communications that are culturally appropriate and palatable to fishers. We argue that the application of social learning principles in communications about climate change may be one constructive way forward.

Abstract Marine policymakers are facing increasing calls to consider the resilience of communities that rely on coastal and marine ecosystem goods and services, and the resilience of natural systems themselves. These calls are in response to increasing threats to coastal communities from external factors such as coastal hazards, possibly associated with climate change, reductions in natural capital often caused by over-fishing and invasive species, and drivers that act to change local and regional economic conditions leading to changes in employment and inequality. However, most communities have had little experience in explicitly managing for resilience. Similarly, our understanding of the factors that make a natural or social system resilient is also somewhat limited. Furthermore, there is a lack of consensus-based definitions and performance measures for assessing resilience. These factors, along with other barriers, will need to be overcome before effective resilience-based management can be implemented.

Abstract International shipping carries around 80 per cent of global trade by volume and over 70 per cent by value. However, there is concern that the greenhouse gas (GHG) emissions from international shipping lead to adverse effects on climate, human health and marine ecosystems. Currently the international climate change regime under the United Nations Framework Convention on Climate Change ( UNFCCC ) process and the IMO through its Marine Environment Protection Committee are grappling with this issue, and GHG emissions from international shipping have been partially regulated by amendments to Annex VI to the International Convention for the Prevention of Pollution from Ships ( MARPOL 73/78 ) in 2011 and 2014. These amendments aim to reduce GHG emissions from international shipping by means of technical and operational measures. However, research indicates that the adopted technical and operational measures alone would not achieve absolute emissions reduction due to projected growth of international seaborne trade. Currently it is still controversial whether it is time to consider market-based measures (MBMs) in furthering the reduction of shipping GHG emissions. This article examines whether it is necessary to adopt MBMs, proposes a preferred MBM, and suggests that a MBM be considered in or after 2016.

A mesocosm approach was used to investigate the effects of ocean acidification (OA) on a natural plankton community in coastal waters off Norway by manipulating CO2 partial pressure (pCO2). Eight enclosures were deployed in the Raunefjord near Bergen. Treatment levels were ambient (~320 µatm) and elevated pCO2 (~2000 µatm), each in 4 replicate enclosures. The experiment lasted for 53 d in May-June 2015. To assess impacts of OA on the plankton community, phytoplankton and protozooplankton biomass and total seston fatty acid content were analyzed. In both treatments, the plankton community was dominated by the dinoflagellate Ceratium longipes. In the elevated pCO2 treatment, however, biomass of this species as well as that of other dinoflagellates was strongly negatively affected. At the end of the experiment, total dinoflagellate biomass was 4-fold higher in the control group than under elevated pCO2 conditions. In a size comparison of C. longipes, cell size in the high pCO2 treatment was significantly larger. The ratio of polyunsaturated fatty acids to saturated fatty acids of seston decreased at high pCO2. In particular, the concentration of docosahexaenoic acid (C 22:6n3c), essential for development and reproduction of metazoans, was less than half at high pCO2 compared to ambient pCO2. Thus, elevated pCO2 led to a deterioration in the quality and quantity of food in a natural plankton community, with potential consequences for the transfer of matter and energy to higher trophic levels

AbstractAimExperimental simulation of near‐future ocean acidification (OA) has been demonstrated to affect growth and development of echinoderm larval stages through energy allocation towards ion and pH compensatory processes. To date, it remains largely unknown how major pH regulatory systems and their energetics are affected by trans‐generational exposure to near‐future acidification levels.MethodsHere, we used the common sea star Asterias rubens in a reciprocal transplant experiment comprising different combinations of OA scenarios, to study trans‐generational plasticity using morphological and physiological endpoints.ResultsAcclimation of adults to pHT 7.2 (pCO2 3500 μatm) led to reductions in feeding rates, gonad weight and fecundity. No effects were evident at moderate acidification levels (pHT 7.4; pCO2 2000 μatm). Parental pre‐acclimation to pHT 7.2 for 85 days reduced developmental rates even when larvae were raised under moderate and high pH conditions, whereas pre‐acclimation to pHT 7.4 did not alter offspring performance. Microelectrode measurements and pharmacological inhibitor studies carried out on larval stages demonstrated that maintenance of alkaline gastric pH represents a substantial energy sink under acidified conditions that may contribute up to 30% to the total energy budget.ConclusionParental pre‐acclimation to acidification levels that are beyond the pH that is encountered by this population in its natural habitat (eg, pHT 7.2) negatively affected larval size and development, potentially through reduced energy transfer. Maintenance of alkaline gastric pH and reductions in maternal energy reserves probably constitute the main factors for a reduced juvenile recruitment of this marine keystone species under simulated OA.

Abstract Blue carbon produced by marine ranching has tremendous economic and ecological value. A sound blue carbon trading mechanism, a fair market environment, and an effective supervision framework will help to transform and upgrade the marine economy through blue carbon trading. The present study develops a three-party evolutionary game model, that consists of the government supervisory agency, the blue carbon trading platform, and the news media, to analyse the evolutionary equilibrium conditions and each party’s evolutionarily stable strategy. It also performs numerical simulations on the evolution strategies. The study results demonstrate: (1) More strict supervision from the government will prevent the platform from engaging in opportunistic behaviours, and ensure fairness in blue carbon trading. (2) The news media’s participation as a watchdog can play a role in restraining the platform’s non-compliance behaviours, but a free-rider issue may also arise, which leads to an absence of supervision. (3) Consumers’ recognition of marine ranching products and the proportion of blue carbon produced by marine ranching that is available for trading will indirectly affect the platform’s course of action. Lastly, the paper makes policy recommendations for the development of a well-functioning blue carbon trading mechanism, a fair market environment, and an effective supervision framework.

Abstract As the population of cities continues to proliferate, society places a greater strain on the productivity of geographical features and their resources. In recent years, this trend has increased for the planet's seas. In order to further maximize the utility of marine space, the concept of co-location between economic sectors operating in the sea, and coexistence of such sectors with the ecosystem, has provided traction for the concept of multi-use (MU). In response, the European Union Horizon 2020 programme funded the Multi-Use in European Seas (MUSES) project which aims to provide innovative technical and policy solutions to facilitate MU in the five European sea basins. Within the broader analytical framework of MUSES, 10 case studies were developed to determine the potentials and effects of MU for various sectors. This paper examines MU between tidal energy development and environmental protection, as well as tidal energy development and environmental monitoring. A desk analysis provided for known drivers, added values, barriers, and impacts of MU. Results from the desk analysis were validated by key stakeholders, resulting in policy and technical recommendations informing the MUSES Action Plan. The analysis demonstrates that technological advancements to monitoring equipment are required to further studies of environmental interactions with tidal energy arrays, and determine the viability of co-locating developments in environmentally sensitive areas. However, greater capacity deployments of tidal energy are required so that robust monitoring data sets can accumulate over time, geographical scope, and ecological make-up. Such capacity development is currently hindered by ineffective government fiscal measures.